Development of a Novel Waste-Based Insulated Plaster with Waterproofing Ability for Roof Slabs

The cement industry contributes significantly to global greenhouse gas emissions, and improving the thermal performance of buildings is crucial for reducing energy consumption and achieving thermal comfort. The building envelope, particularly roof slabs, plays a vital role in heat transfer, accounting for 50–60% of overall heat exchange. Thermal insulation is an effective solution for energy-efficient thermal comfort, and Rice Husk Ash (RHA) is a sustainable material that can enhance thermal insulation and reduce operational energy in roof slabs. Inducing pore structure using RHA for low thermal conductivity and filling the gaps and voids in micro-structure with non-conductive Waste Brick Powder (WBP) were the main concepts of developing this dual-purpose protection while ensuring sustainable construction practices and the reduction of greenhouse gas emissions with controlled waste disposal which turns to timely needed sustainable building materials. This novel product indicated 69.5 and 89% lower values of thermal conductivity and waterproofing abilities, respectively, when compared with average values of available corresponding products in the market.